Add mutli rev support for function describe

src/scmrepo/git/__init__.py

@@ -442,15 +442,23 @@ def _reset(self) -> None:
 
     def describe(
         self,
-        rev: str,
+        revs: Iterable[str],
         base: Optional[str] = None,
         match: Optional[str] = None,
         exclude: Optional[str] = None,
-    ) -> Optional[str]:
-        if (
-            base == "refs/heads"
-            and self.get_rev() == rev
-            and self.get_ref("HEAD", follow=False).startswith(base)
-        ):
-            return self.get_ref("HEAD", follow=False)
-        return self._describe(rev, base, match, exclude)
+    ) -> Dict[str, Optional[str]]:
+        results: Dict[str, Optional[str]] = {}
+        remained_revs = set()
+        if base == "refs/heads":
+            current_rev = self.get_rev()
+            head_ref = self.get_ref("HEAD", follow=False)
+            for rev in revs:
+                if current_rev == rev and head_ref.startswith(base):
+                    results[rev] = self.get_ref("HEAD", follow=False)
+                else:
+                    remained_revs.add(rev)
+        else:
+            remained_revs = set(revs)
+        if remained_revs:
+            results.update(self._describe(remained_revs, base, match, exclude))
+        return results

src/scmrepo/git/backend/base.py

@@ -297,12 +297,12 @@ def _stash_drop(self, ref: str, index: int):
     @abstractmethod
     def _describe(
         self,
-        rev: str,
+        revs: Iterable[str],
         base: Optional[str] = None,
         match: Optional[str] = None,
         exclude: Optional[str] = None,
-    ) -> Optional[str]:
-        """Return the first ref which points to rev.
+    ) -> Mapping[str, Optional[str]]:
+        """Return the first ref which points to each revs.
 
         Roughly equivalent to `git describe --all --exact-match`.
 

src/scmrepo/git/backend/dulwich/__init__.py

@@ -724,21 +724,26 @@ def _stash_drop(self, ref: str, index: int):
 
     def _describe(
         self,
-        rev: str,
+        revs: Iterable[str],
         base: Optional[str] = None,
         match: Optional[str] = None,
         exclude: Optional[str] = None,
-    ) -> Optional[str]:
+    ) -> Mapping[str, Optional[str]]:
         if not base:
             base = "refs/tags"
+        rev_mapping: Dict[str, Optional[str]] = {}
+        results: Dict[str, Optional[str]] = {}
         for ref in self.iter_refs(base=base):
             if (match and not fnmatch.fnmatch(ref, match)) or (
                 exclude and fnmatch.fnmatch(ref, exclude)
             ):
                 continue
-            if self.get_ref(ref, follow=False) == rev:
-                return ref
-        return None
+            revision = self.get_ref(ref, follow=False)
+            if revision and revision not in rev_mapping:
+                rev_mapping[revision] = ref
+        for rev in revs:
+            results[rev] = rev_mapping.get(rev, None)
+        return results
 
     def diff(self, rev_a: str, rev_b: str, binary=False) -> str:
         from dulwich.patch import write_tree_diff

src/scmrepo/git/backend/gitpython.py

@@ -572,11 +572,11 @@ def _stash_drop(self, ref: str, index: int):
 
     def _describe(
         self,
-        rev: str,
+        revs: Iterable[str],
         base: Optional[str] = None,
         match: Optional[str] = None,
         exclude: Optional[str] = None,
-    ) -> Optional[str]:
+    ) -> Mapping[str, Optional[str]]:
         raise NotImplementedError
 
     def diff(self, rev_a: str, rev_b: str, binary=False) -> str:

src/scmrepo/git/backend/pygit2.py

@@ -515,11 +515,11 @@ def _stash_drop(self, ref: str, index: int):
 
     def _describe(
         self,
-        rev: str,
+        revs: Iterable[str],
         base: Optional[str] = None,
         match: Optional[str] = None,
         exclude: Optional[str] = None,
-    ) -> Optional[str]:
+    ) -> Mapping[str, Optional[str]]:
         raise NotImplementedError
 
     def diff(self, rev_a: str, rev_b: str, binary=False) -> str:

tests/test_git.py

@@ -705,21 +705,28 @@ def test_describe(tmp_dir: TmpDir, scm: Git, git: Git):
     scm.add_commit("foo", message="bar")
     rev_bar = scm.get_rev()
 
-    assert git.describe(rev_foo, "refs/heads") is None
+    assert git.describe([rev_foo], "refs/heads") == {rev_foo: None}
 
     scm.checkout("branch", create_new=True)
-    assert git.describe(rev_bar, "refs/heads") == "refs/heads/branch"
+    assert git.describe([rev_bar], "refs/heads") == {
+        rev_bar: "refs/heads/branch"
+    }
 
     tmp_dir.gen({"foo": "foobar"})
     scm.add_commit("foo", message="foobar")
     rev_foobar = scm.get_rev()
 
     scm.checkout("master")
-    assert git.describe(rev_bar, "refs/heads") == "refs/heads/master"
-    assert git.describe(rev_foobar, "refs/heads") == "refs/heads/branch"
+    assert git.describe([rev_bar, rev_foobar], "refs/heads") == {
+        rev_bar: "refs/heads/master",
+        rev_foobar: "refs/heads/branch",
+    }
 
     scm.tag("tag")
-    assert git.describe(rev_bar) == "refs/tags/tag"
+    assert git.describe([rev_bar, "nonexist"]) == {
+        rev_bar: "refs/tags/tag",
+        "nonexist": None,
+    }
 
 
 def test_ignore(tmp_dir: TmpDir, scm: Git, git: Git):